Brush 21 is this 2010 Ford F-350/CET, 20/200.
In 2010, a retired Sheriff for Berkeley County won the state lottery. He donated a truck to each volunteer department in the county, as well as several ambulances and vehicles for the Sheriff's Department.
The Sheriff saw the difficulties the department's would have during bad weather and wanted to better equip them with a 4 wheel drive vehicle. Brush 21 was one of these units.